with \(V=a^3(T){\tilde{L}}^2L\) .
The last equality indicates that this term
can be identified with the thermal entropy.
The factor 3/4 is attributed to the fact that the theory is
strongly coupled and thus
the expression for the entropy deviates from the perturbative prediction [1]}. The first term in eq. (REF ) is the
contribution to the entropy arising from the strong entanglement of
degrees of freedom in the vicinity of the
entangling surface. It displays the expected divergence associated with
short distances on either side of this surface. The entanglement entropy is
proportional to the proper area of the entangling surface, which is now
time-dependent. There is no logarithmic divergence for a slab configuration, so that
the last two terms are finite contributions proportional
to the area. The first of these terms is temperature-dependent, while the
last one arises through the expansion [2]}. It is noteworthy that
no volume term associated with purely quantum entanglement arises.
